1. Field of the Invention
The present invention relates to a vehicle seat assembly. More particularly, the present invention relates to a harmonic drive disc recliner operatively coupling a seat back and seat cushion.
2. Description of Related Art
Automotive vehicles typically include one or more seat assemblies having a seat cushion and a seat back for supporting passengers above a vehicle floor. The seat assembly is commonly mounted directly to the vehicle floor or, more commonly, the seat assembly is operatively coupled to the floor by a seat track assembly for providing fore and aft sliding adjustment of the seat assembly for passenger comfort. The seat back is typically operatively coupled to the seat cushion by a recliner assembly for providing pivotal movement relative to the seat cushion.
For some vehicles, particularly those for the luxury market, the recliner assembly is electrically powered. A typical power seat recliner assembly includes an electric drive motor that meshes with a series of reduction gears. Rotation of the drive motor adjusts the recline angle of the seat back relative to the seat cushion. Forward and rearward reclining movement of the seat back is provided through reversing the direction of rotation of the drive motor.
It is desirable that an improved recliner assembly be compact, lightweight and low-cost. It is also desirable that an improved recliner assembly reduce any gear backlash or “chuck.” “Chuck” refers to any imperfection or play within the recliner assembly that allows movement of the seat back while the recliner assembly is in a locked condition. Further, it is desirable that an improved recliner assembly allows for a high gear ratio which allows for a smaller drive motor and less drive motor gear reduction.